51
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Deng Y, Qiao L, Du M, Qu C, Wan L, Li J, Huang L. Age-related macular degeneration: Epidemiology, genetics, pathophysiology, diagnosis, and targeted therapy. Genes Dis 2022; 9:62-79. [PMID: 35005108 PMCID: PMC8720701 DOI: 10.1016/j.gendis.2021.02.009] [Citation(s) in RCA: 105] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 01/17/2021] [Accepted: 02/21/2021] [Indexed: 12/15/2022] Open
Abstract
Age-related macular degeneration (AMD) is a complex eye disorder and is the leading cause of incurable blindness worldwide in the elderly. Clinically, AMD initially affects the central area of retina known as the macula and it is classified as early stage to late stage (advanced AMD). The advanced AMD is classified into the nonexudative or atrophic form (dry AMD) and the exudative or neovascular form (wet AMD). More severe vision loss is typically associated with the wet form. Multiple genetic factors, lipid metabolism, oxidative stress and aging, play a role in the etiology of AMD. Dysregulation in genetic to AMD is established to 46%-71% of disease contribution, with CFH and ARMS2/HTRA1 to be the two most notable risk loci among the 103 identified AMD associated loci so far. Chronic cigarette smoking is the most proven consistently risk living habits for AMD. Deep learning algorithm has been developed based on image recognition to distinguish wet AMD and normal macula with high accuracy. Currently, anti-vascular endothelial growth factor (VEGF) therapy is highly effective at treating wet AMD. Several new generation AMD drugs and iPSC-derived RPE cell therapy are in the clinical trial stage and are promising to improve AMD treatment in the near future.
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Affiliation(s)
- Yanhui Deng
- The Key Laboratory for Human Disease Gene Study of Sichuan Province, Department of Clinical Laboratory, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, PR China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences, Sichuan Academy of Medical Sciences, Chengdu, Sichuan 610072, PR China
| | - Lifeng Qiao
- Department of Ophthalmology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, PR China
| | - Mingyan Du
- The Key Laboratory for Human Disease Gene Study of Sichuan Province, Department of Clinical Laboratory, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, PR China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences, Sichuan Academy of Medical Sciences, Chengdu, Sichuan 610072, PR China
| | - Chao Qu
- Department of Ophthalmology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, PR China
| | - Ling Wan
- Department of Ophthalmology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, PR China
| | - Jie Li
- Department of Ophthalmology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, PR China
| | - Lulin Huang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province, Department of Clinical Laboratory, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, PR China
- Institute of Chengdu Biology, Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan 610041, PR China
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52
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Wolf AT, Harris A, Oddone F, Siesky B, Vercellin AV, Ciulla TA. Disease progression pathways of wet AMD: opportunities for new target discovery. Expert Opin Ther Targets 2022; 26:5-12. [PMID: 35060431 PMCID: PMC8915198 DOI: 10.1080/14728222.2022.2030706] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among people age 60 years or older in developed countries. Current standard-of-care anti-vascular endothelial growth factor (VEGF) therapy, which inhibits angiogenesis and vascular permeability, has been shown to stabilize choroidal neovascularization and increase visual acuity in neovascular AMD. However, therapeutic limitations of anti-VEGF therapy include limited durability with consequent need for frequent intravitreal injections, and a ceiling of efficacy. Current strategies under investigation include targeting VEGF-C and VEGF-D, integrins, tyrosine kinase receptors, and the Tie2/angiopoietin-2 pathway. A literature search was conducted through November 30, 2021 on PubMed, Medline, Google Scholar, and associated digital platforms with the following keywords: wet macular degeneration, age-related macular degeneration, therapy, VEGF-A, VEGF-C, VEGF-D, integrins, Tie2/Ang2, and tyrosine kinase inhibitors. AREAS COVERED The authors provide a comprehensive review of AMD disease pathways and mechanisms involved in wet AMD as well as novel targets for future therapies. EXPERT OPINION With novel targets and advancements in drug delivery, there is potential to address treatment burden and to improve outcomes for patients afflicted with neovascular AMD.
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Affiliation(s)
- Amber T. Wolf
- Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA
| | - Alon Harris
- Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA
| | | | - Brent Siesky
- Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA
| | | | - Thomas A. Ciulla
- Vitreoretinal Medicine and Surgery, Midwest Eye Institute, Indianapolis, IN, USA
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53
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Tan TE, Fenner BJ, Barathi VA, Tun SBB, Wey YS, Tsai ASH, Su X, Lee SY, Cheung CMG, Wong TY, Mehta JS, Teo KYC. Gene-Based Therapeutics for Acquired Retinal Disease: Opportunities and Progress. Front Genet 2021; 12:795010. [PMID: 34950193 PMCID: PMC8688942 DOI: 10.3389/fgene.2021.795010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/16/2021] [Indexed: 12/22/2022] Open
Abstract
Acquired retinal diseases such as age-related macular degeneration and diabetic retinopathy rank among the leading causes of blindness and visual loss worldwide. Effective treatments for these conditions are available, but often have a high treatment burden, and poor compliance can lead to disappointing real-world outcomes. Development of new treatment strategies that provide more durable treatment effects could help to address some of these unmet needs. Gene-based therapeutics, pioneered for the treatment of monogenic inherited retinal disease, are being actively investigated as new treatments for acquired retinal disease. There are significant advantages to the application of gene-based therapeutics in acquired retinal disease, including the presence of established therapeutic targets and common pathophysiologic pathways between diseases, the lack of genotype-specificity required, and the larger potential treatment population per therapy. Different gene-based therapeutic strategies have been attempted, including gene augmentation therapy to induce in vivo expression of therapeutic molecules, and gene editing to knock down genes encoding specific mediators in disease pathways. We highlight the opportunities and unmet clinical needs in acquired retinal disease, review the progress made thus far with current therapeutic strategies and surgical delivery techniques, and discuss limitations and future directions in the field.
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Affiliation(s)
- Tien-En Tan
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Beau James Fenner
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Veluchamy Amutha Barathi
- Singapore Eye Research Institute, Singapore, Singapore.,Duke-National University of Singapore Medical School, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Sai Bo Bo Tun
- Singapore Eye Research Institute, Singapore, Singapore
| | - Yeo Sia Wey
- Singapore Eye Research Institute, Singapore, Singapore
| | - Andrew Shih Hsiang Tsai
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Xinyi Su
- Singapore Eye Research Institute, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore.,Department of Ophthalmology, National University Hospital, Singapore, Singapore
| | - Shu Yen Lee
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Chui Ming Gemmy Cheung
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Tien Yin Wong
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Jodhbir Singh Mehta
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Kelvin Yi Chong Teo
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-National University of Singapore Medical School, Singapore, Singapore
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54
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Marcos LF, Wilson SL, Roach P. Tissue engineering of the retina: from organoids to microfluidic chips. J Tissue Eng 2021; 12:20417314211059876. [PMID: 34917332 PMCID: PMC8669127 DOI: 10.1177/20417314211059876] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/28/2021] [Indexed: 12/29/2022] Open
Abstract
Despite advancements in tissue engineering, challenges remain for fabricating functional tissues that incorporate essential features including vasculature and complex cellular organisation. Monitoring of engineered tissues also raises difficulties, particularly when cell population maturity is inherent to function. Microfluidic, or lab-on-a-chip, platforms address the complexity issues of conventional 3D models regarding cell numbers and functional connectivity. Regulation of biochemical/biomechanical conditions can create dynamic structures, providing microenvironments that permit tissue formation while quantifying biological processes at a single cell level. Retinal organoids provide relevant cell numbers to mimic in vivo spatiotemporal development, where conventional culture approaches fail. Modern bio-fabrication techniques allow for retinal organoids to be combined with microfluidic devices to create anato-physiologically accurate structures or ‘retina-on-a-chip’ devices that could revolution ocular sciences. Here we present a focussed review of retinal tissue engineering, examining the challenges and how some of these have been overcome using organoids, microfluidics, and bioprinting technologies.
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Affiliation(s)
- Luis F Marcos
- Department of Chemistry, School of Science, Loughborough University, Leicestershire, UK
| | - Samantha L Wilson
- Centre for Biological Engineering, School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Leicestershire, UK
| | - Paul Roach
- Department of Chemistry, School of Science, Loughborough University, Leicestershire, UK
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Varin J, Morival C, Maillard N, Adjali O, Cronin T. Risk Mitigation of Immunogenicity: A Key to Personalized Retinal Gene Therapy. Int J Mol Sci 2021; 22:12818. [PMID: 34884622 PMCID: PMC8658027 DOI: 10.3390/ijms222312818] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/17/2021] [Accepted: 11/23/2021] [Indexed: 12/27/2022] Open
Abstract
Gene therapy (GT) for ocular disorders has advanced the most among adeno-associated virus (AAV)-mediated therapies, with one product already approved in the market. The bank of retinal gene mutations carefully compiled over 30 years, the small retinal surface that does not require high clinical vector stocks, and the relatively immune-privileged environment of the eye explain such success. However, adverse effects due to AAV-delivery, though rare in the retina have led to the interruption of clinical trials. Risk mitigation, as the key to safe and efficient GT, has become the focus of 'bedside-back-to-bench' studies. Herein, we overview the inflammatory adverse events described in retinal GT trials and analyze which components of the retinal immunological environment might be the most involved in these immune responses, with a focus on the innate immune system composed of microglial surveillance. We consider the factors that can influence inflammation in the retina after GT such as viral sensors in the retinal tissue and CpG content in promoters or transgene sequences. Finally, we consider options to reduce the immunological risk, including dose, modified capsids or exclusion criteria for clinical trials. A better understanding and mitigation of immune risk factors inducing host immunity in AAV-mediated retinal GT is the key to achieving safe and efficient GT.
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Affiliation(s)
| | | | | | - Oumeya Adjali
- CHU de Nantes, INSERM UMR1089, Translational Gene Therapy for Genetic Diseases, Université de Nantes, F-44200 Nantes, France; (J.V.); (C.M.); (N.M.)
| | - Therese Cronin
- CHU de Nantes, INSERM UMR1089, Translational Gene Therapy for Genetic Diseases, Université de Nantes, F-44200 Nantes, France; (J.V.); (C.M.); (N.M.)
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56
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Moraru AD, Costin D, Iorga RE, Munteanu M, Moraru RL, Branisteanu DC. Current trends in gene therapy for retinal diseases (Review). Exp Ther Med 2021; 23:26. [PMID: 34815778 PMCID: PMC8593927 DOI: 10.3892/etm.2021.10948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/10/2021] [Indexed: 11/17/2022] Open
Abstract
The eye is considered an effective target for genetic therapy, as it has a privileged immune status, it is easily accessed for medication delivery and it is affected by a number of inherited disorders. In particular, the retina is considered for gene therapy due to the fact that it can be visualized with ease, it does not have lymphatic vessels, nor a direct blood network for the outer layers and its cells do not divide after birth, and thus transgene expression is not affected. As gene therapy is currently on a continuously progressive development trend, this emerging field of gene manipulation techniques has yielded promising results. This involves the development of treatments for a number of debilitating and blinding diseases, which were to date considered intractable. However, numerous unanswered questions remain as regards the long-term efficacy and safety profile of these treatments. The present review article discusses the current research status regarding genetic manipulation techniques aimed at addressing visual impairment related to retinal disorders, both inherited and degenerative.
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Affiliation(s)
- Andreea Dana Moraru
- Department of Ophthalmology, 'Grigore T. Popa' University of Medicine and Pharmacy, 700115 Iași, Romania.,Department of Ophthalmology, 'N. Oblu' Clinical Hospital, 700309 Iași, Romania
| | - Dănuț Costin
- Department of Ophthalmology, 'Grigore T. Popa' University of Medicine and Pharmacy, 700115 Iași, Romania.,Department of Ophthalmology, 'N. Oblu' Clinical Hospital, 700309 Iași, Romania
| | - Raluca Eugenia Iorga
- Department of Ophthalmology, 'Grigore T. Popa' University of Medicine and Pharmacy, 700115 Iași, Romania.,Department of Ophthalmology, 'N. Oblu' Clinical Hospital, 700309 Iași, Romania
| | - Mihnea Munteanu
- Department of Ophthalmology, 'Victor Babeș' University of Medicine and Pharmacy, 300041 Timișoara, Romania
| | - Radu Lucian Moraru
- Department of Otorhinolaryngology, 'Transmed Expert' Medical Center, 700011 Iași, Romania
| | - Daniel Constantin Branisteanu
- Department of Ophthalmology, 'Grigore T. Popa' University of Medicine and Pharmacy, 700115 Iași, Romania.,Department of Ophthalmology, 'Retina Center' Eye Clinic, 700126 Iași, Romania
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57
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Mellen PL, Heier JS. Gene Therapy for Neovascular Macular Degeneration, Diabetic Retinopathy, and Diabetic Macular Edema. Int Ophthalmol Clin 2021; 61:229-239. [PMID: 34584059 DOI: 10.1097/iio.0000000000000382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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58
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Arepalli S, Kaiser PK. Pipeline therapies for neovascular age related macular degeneration. Int J Retina Vitreous 2021; 7:55. [PMID: 34598731 PMCID: PMC8485527 DOI: 10.1186/s40942-021-00325-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 09/09/2021] [Indexed: 12/22/2022] Open
Abstract
Age related macular degeneration (AMD) is the most common cause of vision loss in the elderly population. Neovascular AMD comprises 10% of all cases and can lead to devastating visual loss due to choroidal neovascularization (CNV). There are various cytokine pathways involved in the formation and leakage from CNV. Prior treatments have included focal laser therapy, verteporfin (Visudyne, Bausch and Lomb, Rochester, New York) ocular photodynamic therapy, transpupillary thermotherapy, intravitreal steroids and surgical excision of choroidal neovascular membranes. Currently, the major therapies in AMD focus on the VEGF-A pathway, of which the most common are bevacizumab (Avastin; Genentech, San Francisco, California), ranibizumab (Lucentis; Genentech, South San Francisco, California), and aflibercept (Eylea; Regeneron, Tarrytown, New York). Anti-VEGF agents have revolutionized our treatment of wet AMD; however, real world studies have shown limited visual improvement in patients over time, largely due to the large treatment burden. Cheaper alternatives, including ranibizumab biosimilars, include razumab (Intas Pharmaceuticals Ltd., Ahmedabad, India), FYB 201 (Formycon AG, Munich, Germany and Bioeq Gmbh Holzkirchen, Germany), SB-11 (Samsung Bioepsis, Incheon, South Korea), xlucane (Xbrane Biopharma, Solna, Sweden), PF582 (Pfnex, San Diego, California), CHS3551 (Coherus BioSciences, Redwood City, California). Additionally, aflibercept biosimilars under development include FYB203 (Formycon AG, Munich, Germany and Bioeq Gmbh Holzkirchen, Germany), ALT-L9 (Alteogen, Deajeon, South Korea), MYL1710 (Momenta Pharamaceuticals, Cambridge, MA, and Mylan Pharmacueticals, Canonsburg, PA), CHS-2020 (Coherus BioSciences, Redwood City, California). Those in the pipeline of VEGF targets include abicipar pegol (Abicipar; Allergan, Coolock, Dublin), OPT-302 (Opthea; OPTHEA limited; Victoria, Melbourne), conbercept (Lumitin; Chengdu Kanghong Pharmaceutical Group, Chengdu, Sichuan), and KSI-301 (Kodiak Sciences, Palo Alto, CA). There are also combination medications, which target VEGF and PDGF, VEGF and tissue factor, VEGF and Tie-2, which this paper will also discuss in depth. Furthermore, long lasting depots, such as the ranibizumab port delivery system (PDS) (Genentech, San Francisco, CA), as well as others are under evaluation. Gene therapy present possible longer treatments options as well and are reviewed here. This paper will highlight the past approved medications as well as pipeline therapies for neovascular AMD.
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Affiliation(s)
| | - Peter K Kaiser
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
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59
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Sarkar A, Junnuthula V, Dyawanapelly S. Ocular Therapeutics and Molecular Delivery Strategies for Neovascular Age-Related Macular Degeneration (nAMD). Int J Mol Sci 2021; 22:10594. [PMID: 34638935 PMCID: PMC8508687 DOI: 10.3390/ijms221910594] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/26/2021] [Accepted: 09/28/2021] [Indexed: 12/12/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of vision loss in geriatric population. Intravitreal (IVT) injections are popular clinical option. Biologics and small molecules offer efficacy but relatively shorter half-life after intravitreal injections. To address these challenges, numerous technologies and therapies are under development. Most of these strategies aim to reduce the frequency of injections, thereby increasing patient compliance and reducing patient-associated burden. Unlike IVT frequent injections, molecular therapies such as cell therapy and gene therapy offer restoration ability hence gained a lot of traction. The recent approval of ocular gene therapy for inherited disease offers new hope in this direction. However, until such breakthrough therapies are available to the majority of patients, antibody therapeutics will be on the shelf, continuing to provide therapeutic benefits. The present review aims to highlight the status of pre-clinical and clinical studies of neovascular AMD treatment modalities including Anti-VEGF therapy, upcoming bispecific antibodies, small molecules, port delivery systems, photodynamic therapy, radiation therapy, gene therapy, cell therapy, and combination therapies.
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Affiliation(s)
- Aira Sarkar
- Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA;
| | | | - Sathish Dyawanapelly
- Department of Pharmaceutical Sciences & Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Mumbai 400019, India
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60
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Chung SH, Frick SL, Yiu G. Targeting vascular endothelial growth factor using retinal gene therapy. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1277. [PMID: 34532414 PMCID: PMC8421957 DOI: 10.21037/atm-20-4417] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/25/2020] [Indexed: 12/12/2022]
Abstract
Pharmacotherapies targeting vascular endothelial growth factor (VEGF) have revolutionized the management for neovascular retinal disorders including diabetic retinopathy and neovascular age-related macular degeneration. However, the burden of frequent injections, high cost, and treatment resistance in some patients remain unresolved. To overcome these challenges, newer generations of anti-angiogenic biological therapies, engineered proteins, implantable delivery systems, and biopolymers are currently being developed to enable more sustained, longer-lasting treatments. The use of gene therapies for pathologic angiogenesis has garnered renewed interests since the first FDA-approval of a gene therapy to treat inherited retinal diseases associated with biallelic RPE65 mutations. Newer generations of viral vectors and novel methods of intraocular injections helped overcome ocular barriers, improving the efficiency of transduction as well as safety profile. In addition, unlike current anti-VEGF gene therapy strategies which employ a biofactory approach to mimic existing pharmacotherapies, novel genome editing strategies that target pro-angiogenic factors at the DNA level offer a unique and distinct mechanistic approach that can potentially be more precise and lead to a permanent cure. Here, we review current anti-VEGF therapies and newer pharmacologic agents under development, examine technologies and progress in adapting anti-VEGF gene therapies, and explore the future application of CRISPR-Cas9 technology to suppress ocular angiogenesis.
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Affiliation(s)
- Sook H Chung
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Sonia L Frick
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Glenn Yiu
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
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Abstract
The beginning of the twenty-first century was marked by the innovative use of pharmacochemical interventions, which have since expanded to include gene-based molecular therapies. For years, treatment has focused on tackling the pathophysiology of monogenic orphan diseases, and one of the first applications of these novel genome editing technologies was the treatment of rare inherited retinal dystrophies. In this review, we present recent, ongoing, and future gene therapy-based treatment trials for choroideremia, X-linked retinitis pigmentosa, Stargardt disease, and age-related macular degeneration. As these trials pave the way toward halting the progression of such devastating diseases, we will begin to see the exciting development of newer, cutting-edge strategies including base editing and prime editing, ushering in a new era of precision medicine.
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Affiliation(s)
- Sarah R Levi
- Jonas Children's Vision Care, Department of Ophthalmology, New York-Presbyterian Hospital, New York, New York 10032, USA; , , ,
| | - Joseph Ryu
- Jonas Children's Vision Care, Department of Ophthalmology, New York-Presbyterian Hospital, New York, New York 10032, USA; , , ,
| | - Pei-Kang Liu
- Jonas Children's Vision Care, Department of Ophthalmology, New York-Presbyterian Hospital, New York, New York 10032, USA; , , , .,Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.,School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Stephen H Tsang
- Jonas Children's Vision Care, Department of Ophthalmology, New York-Presbyterian Hospital, New York, New York 10032, USA; , , , .,Department of Pathology & Cell Biology, Columbia Stem Cell Initiative, New York, New York 10032, USA
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62
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Dhurandhar D, Sahoo NK, Mariappan I, Narayanan R. Gene therapy in retinal diseases: A review. Indian J Ophthalmol 2021; 69:2257-2265. [PMID: 34427196 PMCID: PMC8544052 DOI: 10.4103/ijo.ijo_3117_20] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Over 2 million people worldwide are suffering from gene-related retinal diseases, inherited or acquired, and over 270 genes have been identified which are found to be responsible for these conditions. This review article touches upon the mechanisms of gene therapy, various enzymes of the visual cycle responsible for different genetic diseases, Luxturna—the first US Food and Drug Administration (FDA)-approved therapeutic gene product, and several ongoing trials of gene therapy for age-related macular degeneration. Gene therapy has tremendous potential for retinal conditions due to its ease of accessibility, immune-privileged status, and tight blood-retinal barriers, limiting systemic side effects of the drug. In recent years, advances in gene therapy in retinal conditions have increasing significantly, with progress in cell-specific targeting and transduction efficiency of gene products through the use of adeno-associated viral vectors (AAVs), suggesting that even greater success in future clinical trials is possible.
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Affiliation(s)
- Deven Dhurandhar
- Retina and Uveitis Department, GMR Varalakshmi Campus, LV Prasad Eye Institute, Visakhapatnam, Andhra Pradesh, India
| | - Niroj Kumar Sahoo
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Indumathi Mariappan
- Centre for Ocular Regeneration, Hyderabad Eye Research Foundation, Kallam Anji Reddy Campus, L.V. Prasad Eye Institute, Hyderabad, Telangana, India
| | - Raja Narayanan
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, Telangana, India
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63
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Adak S, Magdalene D, Deshmukh S, Das D, Jaganathan BG. A Review on Mesenchymal Stem Cells for Treatment of Retinal Diseases. Stem Cell Rev Rep 2021; 17:1154-1173. [PMID: 33410097 PMCID: PMC7787584 DOI: 10.1007/s12015-020-10090-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2020] [Indexed: 12/12/2022]
Abstract
Mesenchymal Stem Cells (MSCs) have been studied extensively for the treatment of several retinal diseases. The therapeutic potential of MSCs lies in its ability to differentiate into multiple lineages and secretome enriched with immunomodulatory, anti-angiogenic and neurotrophic factors. Several studies have reported the role of MSCs in repair and regeneration of the damaged retina where the secreted factors from MSCs prevent retinal degeneration, improve retinal morphology and function. MSCs also donate mitochondria to rescue the function of retinal cells and exosomes secreted by MSCs were found to have anti-apoptotic and anti-inflammatory effects. Based on several promising results obtained from the preclinical studies, several clinical trials were initiated to explore the potential advantages of MSCs for the treatment of retinal diseases. This review summarizes the various properties of MSCs that help to repair and restore the damaged retinal cells and its potential for the treatment of retinal degenerative diseases.
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Affiliation(s)
- Sanjucta Adak
- Stem Cells and Cancer Biology Research Group, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Damaris Magdalene
- Department of Strabismus, Sri Sankaradeva Nethralaya Hospital, Guwahati, Assam, India
| | - Saurabh Deshmukh
- Department of Strabismus, Sri Sankaradeva Nethralaya Hospital, Guwahati, Assam, India
| | - Dipankar Das
- Department of Pathology, Sri Sankaradeva Nethralaya Hospital, Guwahati, Assam, India
| | - Bithiah Grace Jaganathan
- Stem Cells and Cancer Biology Research Group, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
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64
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Cheng SY, Luo Y, Malachi A, Ko J, Su Q, Xie J, Tian B, Lin H, Ke X, Zheng Q, Tai PWL, Gao G, Punzo C. Low-Dose Recombinant Adeno-Associated Virus-Mediated Inhibition of Vascular Endothelial Growth Factor Can Treat Neovascular Pathologies Without Inducing Retinal Vasculitis. Hum Gene Ther 2021; 32:649-666. [PMID: 34182803 PMCID: PMC8312021 DOI: 10.1089/hum.2021.132] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The wet form of age-related macular degeneration is characterized by neovascular pathologies that, if untreated, can result in edemas followed by rapid vision loss. Inhibition of vascular endothelial growth factor (VEGF) has been used to successfully treat neovascular pathologies of the eye. Nonetheless, some patients require frequent intravitreal injections of anti-VEGF drugs, increasing the burden and risk of complications from the procedure to affected individuals. Recombinant adeno-associated virus (rAAV)-mediated expression of anti-VEGF proteins is an attractive alternative to reduce risk and burden to patients. However, controversy remains as to the safety of prolonged VEGF inhibition in the eye. Here, we show that two out of four rAAV serotypes tested by intravitreal delivery to express the anti-VEGF drug conbercept lead to a dose-dependent vascular sheathing pathology that is characterized by immune cell infiltrates, reminiscent of vasculitis in humans. We show that this pathology is accompanied by increased expression in vascular cell adhesion molecule 1 (VCAM1) and intercellular adhesion molecule 1 (ICAM1), both of which promote extravasation of immune cells from the vasculature. While formation of the vascular sheathing pathology is prevented in immunodeficient Rag-1 mice that lack B and T cells, increased expression of VACM1 and ICAM1 still occurs, indicating that inhibition of VEGF function leads to expression changes in cell adhesion molecules that promote extravasation of immune cells. Importantly, a 10-fold lower dose of one of the vectors that cause a vascular sheathing pathology is still able to reduce edemas resulting from choroidal neovascularization without causing any vascular sheathing pathology and only a minimal increase in VCAM1 expression. The data suggest that treatments of neovascular eye pathologies with rAAV-mediated expression of anti VEGF drugs can be developed safely. However, viral load needs to be adjusted to the tropisms of the serotype and the expression pattern of the promoter.
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Affiliation(s)
- Shun-Yun Cheng
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Yongwen Luo
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Anneliese Malachi
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Jihye Ko
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Viral Vector Core, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Qin Su
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Viral Vector Core, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Jun Xie
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Bo Tian
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Haijiang Lin
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Xiao Ke
- Chengdu Kanghong Pharmaceutical Group Co. Ltd, Chengdu, Sichuan, China
| | - Qiang Zheng
- Chengdu Kanghong Pharmaceutical Group Co. Ltd, Chengdu, Sichuan, China
| | - Phillip W L Tai
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Claudio Punzo
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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65
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Xu D, Khan MA, Klufas MA, Ho AC. Administration of Ocular Gene Therapy. Int Ophthalmol Clin 2021; 61:131-149. [PMID: 34196321 DOI: 10.1097/iio.0000000000000365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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66
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Mehta N, Robbins DA, Yiu G. Ocular Inflammation and Treatment Emergent Adverse Events in Retinal Gene Therapy. Int Ophthalmol Clin 2021; 61:151-177. [PMID: 34196322 PMCID: PMC8259781 DOI: 10.1097/iio.0000000000000366] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Neesurg Mehta
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA
| | - Deborah Ahn Robbins
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA
| | - Glenn Yiu
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA
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67
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Flores R, Carneiro Â, Vieira M, Tenreiro S, Seabra MC. Age-Related Macular Degeneration: Pathophysiology, Management, and Future Perspectives. Ophthalmologica 2021; 244:495-511. [PMID: 34130290 DOI: 10.1159/000517520] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 05/20/2021] [Indexed: 11/19/2022]
Affiliation(s)
- Rita Flores
- Department of Ophthalmology, Centro Hospitalar de Lisboa Central EPE, Lisbon, Portugal
- iNOVA4Health, CEDOC, NOVA Medical School, NMS, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Ângela Carneiro
- Department of Ophthalmology, Centro Hospitalar Universitário de São João, Porto, Portugal
| | - Miguel Vieira
- Department of Ophthalmology, Centro Hospitalar de Lisboa Central EPE, Lisbon, Portugal
| | - Sandra Tenreiro
- iNOVA4Health, CEDOC, NOVA Medical School, NMS, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Miguel C Seabra
- iNOVA4Health, CEDOC, NOVA Medical School, NMS, Universidade Nova de Lisboa, Lisboa, Portugal
- UCL Institute of Ophthalmology, London, United Kingdom
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68
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Meng LH, Chen YX. Lipid accumulation and protein modifications of Bruch's membrane in age-related macular degeneration. Int J Ophthalmol 2021; 14:766-773. [PMID: 34012894 DOI: 10.18240/ijo.2021.05.19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 02/26/2021] [Indexed: 12/26/2022] Open
Abstract
Age-related macular degeneration (AMD) is a progressive retinal disease, which is the leading cause of blindness in western countries. There is an urgency to establish new therapeutic strategies that could prevent or delay the progression of AMD more efficiently. Until now, the pathogenesis of AMD has remained unclear, limiting the development of the novel therapy. Bruch's membrane (BM) goes through remarkable changes in AMD, playing a significant role during the disease course. The main aim of this review is to present the crucial processes that occur at the level of BM, with special consideration of the lipid accumulation and protein modifications. Besides, some therapies targeted at these molecules and the construction of BM in tissue engineering of retinal pigment epithelium (RPE) cells transplantation were listed. Hopefully, this review may provide a reference for researchers engaged in pathogenesis or management on AMD.
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Affiliation(s)
- Li-Hui Meng
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.,Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - You-Xin Chen
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.,Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
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69
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The Evolution of Fabrication Methods in Human Retina Regeneration. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11094102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Optic nerve and retinal diseases such as age-related macular degeneration and inherited retinal dystrophies (IRDs) often cause permanent sight loss. Currently, a limited number of retinal diseases can be treated. Hence, new strategies are needed. Regenerative medicine and especially tissue engineering have recently emerged as promising alternatives to repair retinal degeneration and recover vision. Here, we provide an overview of retinal anatomy and diseases and a comprehensive review of retinal regeneration approaches. In the first part of the review, we present scaffold-free approaches such as gene therapy and cell sheet technology while in the second part, we focus on fabrication techniques to produce a retinal scaffold with a particular emphasis on recent trends and advances in fabrication techniques. To this end, the use of electrospinning, 3D bioprinting and lithography in retinal regeneration was explored.
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70
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Whitehead M, Osborne A, Yu-Wai-Man P, Martin K. Humoral immune responses to AAV gene therapy in the ocular compartment. Biol Rev Camb Philos Soc 2021; 96:1616-1644. [PMID: 33837614 DOI: 10.1111/brv.12718] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 12/11/2022]
Abstract
Viral vectors can be utilised to deliver therapeutic genes to diseased cells. Adeno-associated virus (AAV) is a commonly used viral vector that is favoured for its ability to infect a wide range of tissues whilst displaying limited toxicity and immunogenicity. Most humans harbour anti-AAV neutralising antibodies (NAbs) due to subclinical infections by wild-type virus during infancy and these pre-existing NAbs can limit the efficiency of gene transfer depending on the target cell type, route of administration and choice of serotype. Vector administration can also result in de novo NAb synthesis that could limit the opportunity for repeated gene transfer to diseased sites. A number of strategies have been described in preclinical models that could circumvent NAb responses in humans, however, the successful translation of these innovations into the clinical arena has been limited. Here, we provide a comprehensive review of the humoral immune response to AAV gene therapy in the ocular compartment. We cover basic AAV biology and clinical application, the role of pre-existing and induced NAbs, and possible approaches to overcoming antibody responses. We conclude with a framework for a comprehensive strategy for circumventing humoral immune responses to AAV in the future.
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Affiliation(s)
- Michael Whitehead
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, U.K
| | - Andrew Osborne
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, U.K
| | - Patrick Yu-Wai-Man
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, U.K.,MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, U.K.,NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, U.K
| | - Keith Martin
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, U.K.,Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, U.K.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
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71
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[Implementation of a new gene therapy in ophthalmology: Regulatory and organizational issues]. J Fr Ophtalmol 2021; 44:730-737. [PMID: 33838946 DOI: 10.1016/j.jfo.2020.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/20/2020] [Accepted: 10/27/2020] [Indexed: 11/23/2022]
Abstract
Voretigene neparvovec (VN) is the first gene therapy in ophthalmology for patients with RPE65-mediated hereditary retinal dystrophy. It has recently obtained European market approval, which is subject to strict regulatory and organizational conditions for its use. Here, we analyze the main studies supporting the authorization of this new therapy and describe the necessary steps to take at a hospital level for optimal administration to patients following current regulations.
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72
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Annamalai B, Parsons N, Nicholson C, Obert E, Jones B, Rohrer B. Subretinal Rather Than Intravitreal Adeno-Associated Virus-Mediated Delivery of a Complement Alternative Pathway Inhibitor Is Effective in a Mouse Model of RPE Damage. Invest Ophthalmol Vis Sci 2021; 62:11. [PMID: 33830174 PMCID: PMC8039473 DOI: 10.1167/iovs.62.4.11] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/04/2021] [Indexed: 12/14/2022] Open
Abstract
Purpose The risk for age-related macular degeneration has been tied to an overactive complement system. Despite combined attempts by academia and industry to develop therapeutics that modulate the complement response, particularly in the late geographic atrophy form of advanced AMD, to date, there is no effective treatment. We have previously demonstrated that pathology in the smoke-induced ocular pathology (SIOP) model, a model with similarities to dry AMD, is dependent on activation of the alternative complement pathway and that a novel complement activation site targeted inhibitor of the alternative pathway can be delivered to ocular tissues via an adeno-associated virus (AAV). Methods Two different viral vectors for specific tissue targeting were compared: AAV5-VMD2-CR2-fH for delivery to the retinal pigment epithelium (RPE) and AAV2YF-smCBA-CR2-fH for delivery to retinal ganglion cells (RGCs). Efficacy was tested in SIOP (6 months of passive smoke inhalation), assessing visual function (optokinetic responses), retinal structure (optical coherence tomography), and integrity of the RPE and Bruch's membrane (electron microscopy). Protein chemistry was used to assess complement activation, CR2-fH tissue distribution, and CR2-fH transport across the RPE. Results RPE- but not RGC-mediated secretion of CR2-fH was found to reduce SIOP and complement activation in RPE/choroid. Bioavailability of CR2-fH in RPE/choroid could be confirmed only after AAV5-VMD2-CR2-fH treatment, and inefficient, adenosine triphosphate-dependent transport of CR2-fH across the RPE was identified. Conclusions Our results suggest that complement inhibition for AMD-like pathology is required basal to the RPE and argues in favor of AAV vector delivery to the RPE or outside the blood-retina barrier.
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Affiliation(s)
- Balasubramaniam Annamalai
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Nathaniel Parsons
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Crystal Nicholson
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Elisabeth Obert
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Bryan Jones
- Department of Ophthalmology, University of Utah, Salt Lake City, Utah, United States
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
- Division of Research, Ralph H. Johnson VA Medical Center, Charleston, South Carolina, United States
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, United States
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73
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Thomas CN, Sim DA, Lee WH, Alfahad N, Dick AD, Denniston AK, Hill LJ. Emerging therapies and their delivery for treating age-related macular degeneration. Br J Pharmacol 2021; 179:1908-1937. [PMID: 33769566 DOI: 10.1111/bph.15459] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/11/2021] [Accepted: 03/14/2021] [Indexed: 12/13/2022] Open
Abstract
Age-related macular degeneration (AMD) is the most common cause of blindness in the Western world and is characterised in its latter stages by retinal cell death and neovascularisation and earlier stages with the loss of parainflammatory homeostasis. Patients with neovascular AMD (nAMD) are treated with frequent intraocular injections of anti-vascular endothelial growth factor (VEGF) therapies, which are not only unpopular with patients but carry risks of sight-threatening complications. A minority of patients are unresponsive with no alternative treatment available, and some patients who respond initially eventually develop a tolerance to treatment. New therapeutics with improved delivery methods and sustainability of clinical effects are required, in particular for non-neovascular AMD (90% of cases and no current approved treatments). There are age-related and disease-related changes that occur which can affect ocular drug delivery. Here, we review the latest emerging therapies for AMD, their delivery routes and implications for translating to clinical practice.
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Affiliation(s)
- Chloe N Thomas
- School of Biomedical Sciences, Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Dawn A Sim
- Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital and University College London Institute of Ophthalmology, London, UK
| | - Wen Hwa Lee
- Action Against AMD, London, UK.,Affordable Medicines Programme, Oxford Martin School, University of Oxford, Oxford, UK
| | - Nada Alfahad
- School of Biomedical Sciences, Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Andrew D Dick
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital and University College London Institute of Ophthalmology, London, UK.,Academic Unit of Ophthalmology, Bristol Medical School and School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Alastair K Denniston
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital and University College London Institute of Ophthalmology, London, UK.,Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.,Department of Ophthalmology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.,Centre for Patient Reported Outcome Research, Institute of Applied Health Research, University of Birmingham, Birmingham, UK.,Birmingham Health Partners Centre for Regulatory Science and Innovation, University of Birmingham, Birmingham, UK.,Health Data Research UK, London, UK
| | - Lisa J Hill
- School of Biomedical Sciences, Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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74
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Chowdhury EA, Meno-Tetang G, Chang HY, Wu S, Huang HW, Jamier T, Chandran J, Shah DK. Current progress and limitations of AAV mediated delivery of protein therapeutic genes and the importance of developing quantitative pharmacokinetic/pharmacodynamic (PK/PD) models. Adv Drug Deliv Rev 2021; 170:214-237. [PMID: 33486008 DOI: 10.1016/j.addr.2021.01.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/17/2022]
Abstract
While protein therapeutics are one of the most successful class of drug molecules, they are expensive and not suited for treating chronic disorders that require long-term dosing. Adeno-associated virus (AAV) mediated in vivo gene therapy represents a viable alternative, which can deliver the genes of protein therapeutics to produce long-term expression of proteins in target tissues. Ongoing clinical trials and recent regulatory approvals demonstrate great interest in these therapeutics, however, there is a lack of understanding regarding their cellular disposition, whole-body disposition, dose-exposure relationship, exposure-response relationship, and how product quality and immunogenicity affects these important properties. In addition, there is a lack of quantitative studies to support the development of pharmacokinetic-pharmacodynamic models, which can support the discovery, development, and clinical translation of this delivery system. In this review, we have provided a state-of-the-art overview of current progress and limitations related to AAV mediated delivery of protein therapeutic genes, along with our perspective on the steps that need to be taken to improve clinical translation of this therapeutic modality.
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75
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Komáromy AM, Koehl KL, Park SA. Looking into the future: Gene and cell therapies for glaucoma. Vet Ophthalmol 2021; 24 Suppl 1:16-33. [PMID: 33411993 PMCID: PMC7979454 DOI: 10.1111/vop.12858] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 12/21/2020] [Indexed: 12/17/2022]
Abstract
Glaucoma is a complex group of optic neuropathies that affects both humans and animals. Intraocular pressure (IOP) elevation is a major risk factor that results in the loss of retinal ganglion cells (RGCs) and their axons. Currently, lowering IOP by medical and surgical methods is the only approved treatment for primary glaucoma, but there is no cure, and vision loss often progresses despite therapy. Recent technologic advances provide us with a better understanding of disease mechanisms and risk factors; this will permit earlier diagnosis of glaucoma and initiation of therapy sooner and more effectively. Gene and cell therapies are well suited to target these mechanisms specifically with the potential to achieve a lasting therapeutic effect. Much progress has been made in laboratory settings to develop these novel therapies for the eye. Gene and cell therapies have already been translated into clinical application for some inherited retinal dystrophies and age-related macular degeneration (AMD). Except for the intravitreal application of ciliary neurotrophic factor (CNTF) by encapsulated cell technology for RGC neuroprotection, there has been no other clinical translation of gene and cell therapies for glaucoma so far. Possible application of gene and cell therapies consists of long-term IOP control via increased aqueous humor drainage, including inhibition of fibrosis following filtration surgery, RGC neuroprotection and neuroregeneration, modification of ocular biomechanics for improved IOP tolerance, and inhibition of inflammation and neovascularization to prevent the development of some forms of secondary glaucoma.
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Affiliation(s)
- András M. Komáromy
- College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Kristin L. Koehl
- College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Shin Ae Park
- College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
- College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
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76
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Potilinski MC, Tate PS, Lorenc VE, Gallo JE. New insights into oxidative stress and immune mechanisms involved in age-related macular degeneration tackled by novel therapies. Neuropharmacology 2021; 188:108513. [PMID: 33662390 DOI: 10.1016/j.neuropharm.2021.108513] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 02/14/2021] [Accepted: 02/22/2021] [Indexed: 12/20/2022]
Abstract
The prevalence of age-related macular degeneration (AMD) has increased in the last years. Although anti-VEGF agents have improved the prognosis of exudative AMD, dry AMD has still devastating effects on elderly people vision. Oxidative stress and inflammation are mechanisms involved in AMD pathogenesis and its progression. Molecular pathways involving epidermal growth factor receptor (EGFR), bone morphogenetic protein (BMP4) and the nuclear erythroid related factor 2 (Nrf2) are behind oxidative stress in AMD due to their participation in antioxidant cellular pathways. As a consequence of the disbalance produced in the antioxidant mechanisms, there is an activation of innate and adaptative immune response with cell recruitment, changes in complement factors expression, and modification of cellular milieu. Different therapies are being studied to treat dry AMD based on the possible effects on antioxidant molecular pathways or their action on the immune response. There is a wide range of treatments presented in this review, from natural antioxidant compounds to cell and gene therapy, based on their mechanisms. Finally, we hypothesize that alpha-1-antitrypsin (AAT), an anti-inflammatory and immunomodulatory molecule that can also modulate antioxidant cellular defenses, could be a good candidate for testing in AMD. This article is part of the special ssue on 'The Quest for Disease-Modifying Therapies for Neurodegenerative Disorders'.
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Affiliation(s)
- María Constanza Potilinski
- Nanomedicine & Vision Lab, Instituto de Investigaciones en Medicina Translacional, Universidad Austral, CONICET, Pilar, Buenos Aires, Argentina
| | - Pablo S Tate
- Laboratorio de Enfermedades Neurodegenerativas, Instituto de Investigaciones en Medicina Translacional, Universidad Austral, CONICET, Pilar, Buenos Aires, Argentina
| | - Valeria E Lorenc
- Nanomedicine & Vision Lab, Instituto de Investigaciones en Medicina Translacional, Universidad Austral, CONICET, Pilar, Buenos Aires, Argentina
| | - Juan E Gallo
- Nanomedicine & Vision Lab, Instituto de Investigaciones en Medicina Translacional, Universidad Austral, CONICET, Pilar, Buenos Aires, Argentina; Departamento de Oftalmología, Hospital Universitario Austral, Pilar, Buenos Aires, Argentina.
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77
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Koponen S, Kokki E, Kinnunen K, Ylä-Herttuala S. Viral-Vector-Delivered Anti-Angiogenic Therapies to the Eye. Pharmaceutics 2021; 13:pharmaceutics13020219. [PMID: 33562561 PMCID: PMC7915489 DOI: 10.3390/pharmaceutics13020219] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/31/2021] [Accepted: 02/02/2021] [Indexed: 12/17/2022] Open
Abstract
Pathological vessel growth harms vision and may finally lead to vision loss. Anti-angiogenic gene therapy with viral vectors for ocular neovascularization has shown great promise in preclinical studies. Most of the studies have been conducted with different adeno-associated serotype vectors. In addition, adeno- and lentivirus vectors have been used. Therapy has been targeted towards blocking vascular endothelial growth factors or other pro-angiogenic factors. Clinical trials of intraocular gene therapy for neovascularization have shown the treatment to be safe without severe adverse events or systemic effects. Nevertheless, clinical studies have not proceeded further than Phase 2 trials.
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Affiliation(s)
- Sanna Koponen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; (S.K.); (E.K.)
| | - Emmi Kokki
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; (S.K.); (E.K.)
| | - Kati Kinnunen
- Department of Ophthalmology, Kuopio University Hospital, 70211 Kuopio, Finland;
| | - Seppo Ylä-Herttuala
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; (S.K.); (E.K.)
- Gene Therapy Unit, Kuopio University Hospital, 70211 Kuopio, Finland
- Correspondence: ; Tel./Fax: +358-403-552-075
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78
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Proteosomal degradation impairs transcytosis of AAV vectors from suprachoroidal space to retina. Gene Ther 2021; 28:740-747. [PMID: 33542456 PMCID: PMC8333227 DOI: 10.1038/s41434-021-00233-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/21/2020] [Accepted: 01/21/2021] [Indexed: 01/18/2023]
Abstract
Suprachoroidal injection provides a new route of delivery for AAV vectors to retinal pigmented epithelial cells and photoreceptors that can be done in an outpatient setting and is less invasive and potentially safer than subretinal injection, the most common route of delivery for ocular gene therapy. After suprachoroidal injection of AAV8 or AAV9 vectors, there is strong transduction of photoreceptors, but it is unclear how vector traverses the retinal pigmented epithelium. In this study, we found that transduction of photoreceptors was significantly increased after suprachoroidal injection of AAV2tYF-CBA-GFP versus AAV2-CBA-GFP vector. Compared with AAV2, AAV2tYF is more resistant to proteosomal degradation. Treatment with protease inhibitors significantly increased photoreceptor transduction after suprachoroidal injection of AAV5-GRK1-GFP. These data suggest that after suprachoroidal injection, AAV vectors access photoreceptors by transcytosis through retinal pigmented epithelial cells during which they are subject to proteosomal degradation, which if suppressed can enhance transduction of photoreceptors.
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79
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Chen J, Lin FL, Leung JYK, Tu L, Wang JH, Chuang YF, Li F, Shen HH, Dusting GJ, Wong VHY, Lisowski L, Hewitt AW, Bui BV, Zhong J, Liu GS. A drug-tunable Flt23k gene therapy for controlled intervention in retinal neovascularization. Angiogenesis 2021; 24:97-110. [PMID: 32935224 DOI: 10.1007/s10456-020-09745-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 09/04/2020] [Indexed: 12/15/2022]
Abstract
Gene therapies that chronically suppress vascular endothelial growth factor (VEGF) represent a new approach for managing retinal vascular leakage and neovascularization. However, constitutive suppression of VEGF in the eye may have deleterious side effects. Here, we developed a novel strategy to introduce Flt23k, a decoy receptor that binds intracellular VEGF, fused to the destabilizing domain (DD) of Escherichia coli dihydrofolate reductase (DHFR) into the retina. The expressed DHFR(DD)-Flt23k fusion protein is degraded unless "switched on" by administering a stabilizer; in this case, the antibiotic trimethoprim (TMP). Cells transfected with the DHFR(DD)-Flt23k construct expressed the fusion protein at levels correlated with the TMP dose. Stabilization of the DHFR(DD)-Flt23k fusion protein by TMP was able to inhibit intracellular VEGF in hypoxic cells. Intravitreal injection of self-complementary adeno-associated viral vector (scAAV)-DHFR(DD)-Flt23k and subsequent administration of TMP resulted in tunable suppression of ischemia-induced retinal neovascularization in a rat model of oxygen-induced retinopathy (OIR). Hence, our study suggests a promising novel approach for the treatment of retinal neovascularization. Schematic diagram of the tunable system utilizing the DHFR(DD)-Flt23k approach to reduce VEGF secretion. a The schematic shows normal VEGF secretion. b Without the ligand TMP, the DHFR(DD)-Flt23k protein is destabilized and degraded by the proteasome. c In the presence of the ligand TMP, DHFR(DD)-Flt23k is stabilized and sequestered in the ER, thereby conditionally inhibiting VEGF. Green lines indicate the intracellular and extracellular distributions of VEGF. Blue lines indicate proteasomal degradation of the DHFR(DD)-Flt23k protein. Orange lines indicate the uptake of cell-permeable TMP. TMP, trimethoprim; VEGF, vascular endothelial growth factor; ER, endoplasmic reticulum.
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Affiliation(s)
- Jinying Chen
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Fan-Li Lin
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China
| | - Jacqueline Y K Leung
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, TAS, Australia
| | - Leilei Tu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Jiang-Hui Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Yu-Fan Chuang
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, TAS, Australia
| | - Fan Li
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Hsin-Hui Shen
- Department of Materials Science and Engineering, Faculty of Engineering, Monash University, Clayton, VIC, Australia
- Department of Biochemistry and Molecular Biology, School of Biomedical Science, Monash University, Clayton, VIC, Australia
| | - Gregory J Dusting
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, VIC, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Leszek Lisowski
- Translational Vectorology Group, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Vector and Genome Engineering Facility, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Military Institute of Hygiene and Epidemiology, The Biological Threats Identification and Countermeasure Centre, Puławy, Poland
| | - Alex W Hewitt
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, VIC, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Jingxiang Zhong
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Guei-Sheung Liu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China.
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia.
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, VIC, Australia.
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80
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Huang L, Wan J, Wu Y, Tian Y, Yao Y, Yao S, Ji X, Wang S, Su Z, Xu H. Challenges in adeno-associated virus-based treatment of central nervous system diseases through systemic injection. Life Sci 2021; 270:119142. [PMID: 33524419 DOI: 10.1016/j.lfs.2021.119142] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 12/19/2022]
Abstract
Adeno-associated virus (AAV) vector, an excellent gene therapy vector, has been widely used in the treatment of various central nervous system (CNS) diseases. Due to the presence of the blood-brain barrier (BBB), early attempts at AAV-based CNS diseases treatment were mainly performed through intracranial injections. Subsequently, systemic injections of AAV9, the first AAV that was shown to have BBB-crossing ability in newborn and adult mice, were assessed in clinical trials for multiple CNS diseases. However, the development of systemic AAV injections to treat CNS diseases is still associated with many challenges, such as the efficiency of AAV in crossing the BBB, the peripheral toxicity caused by the expression of AAV-delivered genes, and the immune barrier against AAV in the blood. In this review, we will introduce the biology of the AAV vector and the advantages of systemic AAV injections to treat CNS diseases. Most importantly, we will introduce the challenges associated with systemic injection of therapeutic AAV in treating CNS diseases and suggest feasible solutions.
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Affiliation(s)
- Lan Huang
- Department of Immunology, Jiangsu University, Zhenjiang 212013, China
| | - Jie Wan
- Department of Immunology, Jiangsu University, Zhenjiang 212013, China; Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Yinqiu Wu
- Department of Immunology, Jiangsu University, Zhenjiang 212013, China
| | - Yu Tian
- Department of Immunology, Jiangsu University, Zhenjiang 212013, China
| | - Yizheng Yao
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Shun Yao
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Xiaoyun Ji
- Department of Immunology, Jiangsu University, Zhenjiang 212013, China
| | - Shengjun Wang
- Department of Immunology, Jiangsu University, Zhenjiang 212013, China
| | - Zhaoliang Su
- Department of Immunology, Jiangsu University, Zhenjiang 212013, China
| | - Huaxi Xu
- Department of Immunology, Jiangsu University, Zhenjiang 212013, China.
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81
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Ruan Y, Jiang S, Gericke A. Age-Related Macular Degeneration: Role of Oxidative Stress and Blood Vessels. Int J Mol Sci 2021; 22:ijms22031296. [PMID: 33525498 PMCID: PMC7866075 DOI: 10.3390/ijms22031296] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Age-related macular degeneration (AMD) is a common irreversible ocular disease characterized by vision impairment among older people. Many risk factors are related to AMD and interact with each other in its pathogenesis. Notably, oxidative stress and choroidal vascular dysfunction were suggested to be critically involved in AMD pathogenesis. In this review, we give an overview on the factors contributing to the pathophysiology of this multifactorial disease and discuss the role of reactive oxygen species and vascular function in more detail. Moreover, we give an overview on therapeutic strategies for patients suffering from AMD.
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Affiliation(s)
- Yue Ruan
- Correspondence: (Y.R.); (A.G.); Tel.: +49-6131-178-276 (Y.R. & A.G.)
| | | | - Adrian Gericke
- Correspondence: (Y.R.); (A.G.); Tel.: +49-6131-178-276 (Y.R. & A.G.)
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82
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Lee KS, Lin S, Copland DA, Dick AD, Liu J. Cellular senescence in the aging retina and developments of senotherapies for age-related macular degeneration. J Neuroinflammation 2021; 18:32. [PMID: 33482879 PMCID: PMC7821689 DOI: 10.1186/s12974-021-02088-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/15/2021] [Indexed: 12/16/2022] Open
Abstract
Age-related macular degeneration (AMD), a degenerative disease in the central macula area of the neuroretina and the supporting retinal pigment epithelium, is the most common cause of vision loss in the elderly. Although advances have been made, treatment to prevent the progressive degeneration is lacking. Besides the association of innate immune pathway genes with AMD susceptibility, environmental stress- and cellular senescence-induced alterations in pathways such as metabolic functions and inflammatory responses are also implicated in the pathophysiology of AMD. Cellular senescence is an adaptive cell process in response to noxious stimuli in both mitotic and postmitotic cells, activated by tumor suppressor proteins and prosecuted via an inflammatory secretome. In addition to physiological roles in embryogenesis and tissue regeneration, cellular senescence is augmented with age and contributes to a variety of age-related chronic conditions. Accumulation of senescent cells accompanied by an impairment in the immune-mediated elimination mechanisms results in increased frequency of senescent cells, termed “chronic” senescence. Age-associated senescent cells exhibit abnormal metabolism, increased generation of reactive oxygen species, and a heightened senescence-associated secretory phenotype that nurture a proinflammatory milieu detrimental to neighboring cells. Senescent changes in various retinal and choroidal tissue cells including the retinal pigment epithelium, microglia, neurons, and endothelial cells, contemporaneous with systemic immune aging in both innate and adaptive cells, have emerged as important contributors to the onset and development of AMD. The repertoire of senotherapeutic strategies such as senolytics, senomorphics, cell cycle regulation, and restoring cell homeostasis targeted both at tissue and systemic levels is expanding with the potential to treat a spectrum of age-related diseases, including AMD.
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Affiliation(s)
- Keng Siang Lee
- Bristol Medical School, Translational Health Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Shuxiao Lin
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
| | - David A Copland
- Bristol Medical School, Translational Health Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Andrew D Dick
- Bristol Medical School, Translational Health Sciences, University of Bristol, Bristol, BS8 1TD, UK. .,Institute of Ophthalmology, University College London, London, EC1V 9EL, UK. .,National Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital, London, EC1V 2QH, UK.
| | - Jian Liu
- Bristol Medical School, Translational Health Sciences, University of Bristol, Bristol, BS8 1TD, UK.
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83
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Xu D, Khan MA, Ho AC. Creating an Ocular Biofactory: Surgical Approaches in Gene Therapy for Acquired Retinal Diseases. Asia Pac J Ophthalmol (Phila) 2021; 10:5-11. [PMID: 33399391 DOI: 10.1097/apo.0000000000000362] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
ABSTRACT Gene therapy offers the potential to treat inherited retinal disorders and deliver sustained therapy for acquired retinal diseases. In the latter case, host cells can be harnessed to produce non-native proteins that have beneficial properties, such as antivascular endothelial growth factor activity, transforming the eye into an ocular "biofactory." Several gene therapy programs have entered clinical testing for delivery to the vitreous, subretinal, and suprachoroidal space. Improved viral vectors and refined surgical techniques are critical to successful delivery of therapeutic products to the target tissue. In this review, we discuss the development of gene therapy products aimed at acquired retinal diseases and the surgical techniques utilized to achieve targeted delivery.
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Affiliation(s)
- David Xu
- Retina Service, Wills Eye Hospital, Philadelphia, PA
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84
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Scott IU, Campochiaro PA, Newman NJ, Biousse V. Retinal vascular occlusions. Lancet 2020; 396:1927-1940. [PMID: 33308475 PMCID: PMC9546635 DOI: 10.1016/s0140-6736(20)31559-2] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 05/29/2020] [Accepted: 07/03/2020] [Indexed: 12/11/2022]
Abstract
Acute retinal vascular occlusions are common causes of visual impairment. Although both retinal artery occlusions and retinal vein occlusions are associated with increased age and cardiovascular risk factors, their pathophysiology, systemic implications, and management differ substantially. Acute management of retinal artery occlusions involves a multidisciplinary approach including neurologists with stroke expertise, whereas treatment of retinal vein occlusions is provided by ophthalmologists. Optimisation of systemic risk factors by patients' primary care providers is an important component of the management of these two disorders.
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Affiliation(s)
- Ingrid U Scott
- Department of Ophthalmology and Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA
| | - Peter A Campochiaro
- Department of Ophthalmology and Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Nancy J Newman
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA; Department of Neurological Surgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Valérie Biousse
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.
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85
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Mendell JR, Al-Zaidy SA, Rodino-Klapac LR, Goodspeed K, Gray SJ, Kay CN, Boye SL, Boye SE, George LA, Salabarria S, Corti M, Byrne BJ, Tremblay JP. Current Clinical Applications of In Vivo Gene Therapy with AAVs. Mol Ther 2020; 29:464-488. [PMID: 33309881 PMCID: PMC7854298 DOI: 10.1016/j.ymthe.2020.12.007] [Citation(s) in RCA: 339] [Impact Index Per Article: 84.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/16/2020] [Accepted: 12/05/2020] [Indexed: 02/07/2023] Open
Abstract
Hereditary diseases are caused by mutations in genes, and more than 7,000 rare diseases affect over 30 million Americans. For more than 30 years, hundreds of researchers have maintained that genetic modifications would provide effective treatments for many inherited human diseases, offering durable and possibly curative clinical benefit with a single treatment. This review is limited to gene therapy using adeno-associated virus (AAV) because the gene delivered by this vector does not integrate into the patient genome and has a low immunogenicity. There are now five treatments approved for commercialization and currently available, i.e., Luxturna, Zolgensma, the two chimeric antigen receptor T cell (CAR-T) therapies (Yescarta and Kymriah), and Strimvelis (the gammaretrovirus approved for adenosine deaminase-severe combined immunodeficiency [ADA-SCID] in Europe). Dozens of other treatments are under clinical trials. The review article presents a broad overview of the field of therapy by in vivo gene transfer. We review gene therapy for neuromuscular disorders (spinal muscular atrophy [SMA]; Duchenne muscular dystrophy [DMD]; X-linked myotubular myopathy [XLMTM]; and diseases of the central nervous system, including Alzheimer’s disease, Parkinson’s disease, Canavan disease, aromatic l-amino acid decarboxylase [AADC] deficiency, and giant axonal neuropathy), ocular disorders (Leber congenital amaurosis, age-related macular degeneration [AMD], choroideremia, achromatopsia, retinitis pigmentosa, and X-linked retinoschisis), the bleeding disorder hemophilia, and lysosomal storage disorders.
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Affiliation(s)
- Jerry R Mendell
- Center of Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics and Neurology, The Ohio State University, Columbus, OH, USA
| | | | | | - Kimberly Goodspeed
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | | | - Sanford L Boye
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
| | - Shannon E Boye
- Division of Cellular and Molecular Therapeutics, University of Florida, Gainesville, FL, USA
| | - Lindsey A George
- Division of Hematology and the Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, PA, USA; Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Stephanie Salabarria
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Manuela Corti
- Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
| | - Barry J Byrne
- Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
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86
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Campochiaro PA, Akhlaq A. Sustained suppression of VEGF for treatment of retinal/choroidal vascular diseases. Prog Retin Eye Res 2020; 83:100921. [PMID: 33248215 DOI: 10.1016/j.preteyeres.2020.100921] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/15/2020] [Accepted: 11/18/2020] [Indexed: 12/27/2022]
Abstract
Neovascular age-related macular degeneration (NVAMD) is the most prevalent choroidal vascular disease, and diabetic retinopathy (DR) and retinal vein occlusion (RVO) are the most prevalent retinal vascular diseases. In each of these, hypoxia plays a central role by stabilizing hypoxia-inducible factor-1 which increases production of vascular endothelial growth factor (VEGF) and other hypoxia-regulated gene products. High VEGF causes excessive vascular permeability, neovascularization, and in DR and RVO, promotes closure of retinal vessels exacerbating hypoxia and creating a positive feedback loop. Hence once VEGF expression is elevated it tends to remain elevated and drives disease progression. While other hypoxia-regulated gene products also contribute to pathology in these disease processes, it is remarkable how much pathology is reversed by selective inhibition of VEGF. Clinical trials have demonstrated outstanding visual outcomes in patients with NVAMD, DR, or RVO from frequent intraocular injections of VEGF-neutralizing proteins, but for a variety of reasons injection frequency has been substantially less in clinical practice and visual outcomes are disappointing. Herein we discuss the rationale, preclinical, and early clinical results of new approaches that provide sustained suppression of VEGF. These approaches will revolutionize the management of these prevalent retinal/choroidal vascular diseases.
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Affiliation(s)
- Peter A Campochiaro
- The Departments of Ophthalmology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
| | - Anam Akhlaq
- The Departments of Ophthalmology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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87
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Kureshi R, Zhu A, Shen J, Tzeng SY, Astrab LR, Sargunas PR, Green JJ, Campochiaro PA, Spangler JB. Structure-Guided Molecular Engineering of a Vascular Endothelial Growth Factor Antagonist to Treat Retinal Diseases. Cell Mol Bioeng 2020; 13:405-418. [PMID: 33184574 DOI: 10.1007/s12195-020-00641-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 07/22/2020] [Indexed: 12/11/2022] Open
Abstract
Background Ocular neovascularization is a hallmark of retinal diseases including neovascular age-related macular degeneration and diabetic retinopathy, two leading causes of blindness in adults. Neovascularization is driven by the interaction of soluble vascular endothelial growth factor (VEGF) ligands with transmembrane VEGF receptors (VEGFR), and inhibition of the VEGF pathway has shown tremendous clinical promise. However, anti-VEGF therapies require invasive intravitreal injections at frequent intervals and high doses, and many patients show incomplete responses to current drugs due to the lack of sustained VEGF signaling suppression. Methods We synthesized insights from structural biology with molecular engineering technologies to engineer an anti-VEGF antagonist protein. Starting from the clinically approved decoy receptor protein aflibercept, we strategically designed a yeast-displayed mutagenic library of variants and isolated clones with superior VEGF affinity compared to the clinical drug. Our lead engineered protein was expressed in the choroidal space of rat eyes via nonviral gene delivery. Results Using a structure-informed directed evolution approach, we identified multiple promising anti-VEGF antagonist proteins with improved target affinity. Improvements were primarily mediated through reduction in dissociation rate, and structurally significant convergent sequence mutations were identified. Nonviral gene transfer of our engineered antagonist protein demonstrated robust and durable expression in the choroid of treated rats one month post-injection. Conclusions We engineered a novel anti-VEGF protein as a new weapon against retinal diseases and demonstrated safe and noninvasive ocular delivery in rats. Furthermore, our structure-guided design approach presents a general strategy for discovery of targeted protein drugs for a vast array of applications.
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Affiliation(s)
- Rakeeb Kureshi
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Angela Zhu
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD USA
| | - Jikui Shen
- Department of Ophthalmology, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD USA.,Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Stephany Y Tzeng
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD USA.,Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD USA.,Insititute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD USA
| | - Leilani R Astrab
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD USA.,Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD USA
| | - Paul R Sargunas
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD USA
| | - Jordan J Green
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD USA.,Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD USA.,Department of Ophthalmology, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD USA.,Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD USA.,Insititute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD USA.,Department of Materials Science & Engineering, Johns Hopkins University, Baltimore, MD USA.,Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Peter A Campochiaro
- Department of Ophthalmology, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD USA.,Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Jamie B Spangler
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD USA.,Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD USA.,Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD USA
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88
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Lin FL, Wang PY, Chuang YF, Wang JH, Wong VHY, Bui BV, Liu GS. Gene Therapy Intervention in Neovascular Eye Disease: A Recent Update. Mol Ther 2020; 28:2120-2138. [PMID: 32649860 PMCID: PMC7544979 DOI: 10.1016/j.ymthe.2020.06.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/15/2020] [Accepted: 06/26/2020] [Indexed: 12/13/2022] Open
Abstract
Aberrant growth of blood vessels (neovascularization) is a key feature of severe eye diseases that can cause legal blindness, including neovascular age-related macular degeneration (nAMD) and diabetic retinopathy (DR). The development of anti-vascular endothelial growth factor (VEGF) agents has revolutionized the treatment of ocular neovascularization. Novel proangiogenic targets, such as angiopoietin and platelet-derived growth factor (PDGF), are under development for patients who respond poorly to anti-VEGF therapy and to reduce adverse effects from long-term VEGF inhibition. A rapidly advancing area is gene therapy, which may provide significant therapeutic benefits. Viral vector-mediated transgene delivery provides the potential for continuous production of antiangiogenic proteins, which would avoid the need for repeated anti-VEGF injections. Gene silencing with RNA interference to target ocular angiogenesis has been investigated in clinical trials. Proof-of-concept gene therapy studies using gene-editing tools such as CRISPR-Cas have already been shown to be effective in suppressing neovascularization in animal models, highlighting the therapeutic potential of the system for treatment of aberrant ocular angiogenesis. This review provides updates on the development of anti-VEGF agents and novel antiangiogenic targets. We also summarize current gene therapy strategies already in clinical trials and those with the latest approaches utilizing CRISPR-Cas gene editing against aberrant ocular neovascularization.
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Affiliation(s)
- Fan-Li Lin
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China; Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Peng-Yuan Wang
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China; Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
| | - Yu-Fan Chuang
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China; Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Jiang-Hui Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC 3010, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC 3010, Australia
| | - Guei-Sheung Liu
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia; Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, VIC 3002, Australia.
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89
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Akyol E, Lotery A. Gene, Cell and Antibody-Based Therapies for the Treatment of Age-Related Macular Degeneration. Biologics 2020; 14:83-94. [PMID: 32982165 PMCID: PMC7494004 DOI: 10.2147/btt.s252581] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/04/2020] [Indexed: 12/30/2022]
Abstract
Here we discuss antibody, cell and gene-based therapies that are currently available and under investigation for both wet and dry age-related macular degeneration (AMD). We initially discuss ocular anatomy, AMD modelling as well as the underlying pathophysiology of AMD. The antibody-based trials which have revolutionised the management of wet AMD are reviewed. The latest concepts in antibody therapy for wet AMD such as the port delivery systems, bispecific antibodies, designed ankyrin repeat protein (DARPINs) and brolucizumab are explored. Furthermore, the antibody-based trials targeting the complement pathway to reduce progression of geographic atrophy (GA) in dry AMD are discussed. Stem cell therapy and gene therapy are novel treatment modalities with no established clinical use in wet or dry AMD. Here, we discuss their efficacy so far in clinical trials. Their benefits and risk in the treatment of both wet and dry AMD are evaluated.
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Affiliation(s)
- Engin Akyol
- Clinical Neurosciences Research Group, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Andrew Lotery
- Clinical Neurosciences Research Group, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
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90
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Vakhshori V, Bougioukli S, Sugiyama O, Kang HP, Tang AH, Park SH, Lieberman JR. Ex vivo regional gene therapy with human adipose-derived stem cells for bone repair. Bone 2020; 138:115524. [PMID: 32622870 PMCID: PMC7423694 DOI: 10.1016/j.bone.2020.115524] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 06/20/2020] [Accepted: 06/29/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND The treatment of complex bone loss scenarios remains challenging. This study evaluates the efficacy of ex vivo regional gene therapy using transduced human adipose-derived stem cells (ASCs) overexpressing bone morphogenetic protein-2 (BMP-2) to treat critical-sized bone defects. METHODS Critical-sized femoral defects created surgically in immunocompromised rats were treated with ASCs transduced with a lentivirus encoding BMP-2 (Group 1, n = 14), or green fluorescent protein (Group 2, n = 5), nontransduced ASCs (Group 3, n = 5), or rhBMP-2 (Group 4, n = 14). At 12 weeks, femurs were evaluated for quantity and quality of bone formation with plain radiographs, micro-computed tomography, histology/histomorphometry, and biomechanical strength testing. RESULTS Thirteen of 14 samples in Group 1 and all 14 samples in Group 4 showed radiographic healing, while no samples in either Groups 2 or 3 healed. Groups 1 and 4 had significantly higher radiographic scores (p < 0.001), bone volume fraction (BV/TV) (p < 0.001), and bone area fraction (BA/TA) than Groups 2 and 3 (p < 0.001). Radiographic scores, BV/TV, and BA/TA were not significantly different between Groups 1 and 4. No difference with regards to mean torque, rotation at failure, torsional stiffness, and energy to failure was seen between Groups 1 and 4. CONCLUSIONS Human ASCs modified to overexpress BMP-2 resulted in abundant bone formation, with the quality of bone comparable to that of rhBMP-2. This strategy represents a promising approach in the treatment of large bone defects in the clinical setting. CLINICAL RELEVANCE Large bone defects may require sustained protein production to induce an appropriate osteoinductive response. Ex vivo regional gene therapy using a lentiviral vector has the potential to be part of a comprehensive tissue engineering strategy for treating osseous defects.
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Affiliation(s)
- Venus Vakhshori
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, 1520 San Pablo Street, Suite 2000, Los Angeles, CA 90033, United States of America.
| | - Sofia Bougioukli
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, 1520 San Pablo Street, Suite 2000, Los Angeles, CA 90033, United States of America
| | - Osamu Sugiyama
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, 1520 San Pablo Street, Suite 2000, Los Angeles, CA 90033, United States of America
| | - Hyunwoo P Kang
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, 1520 San Pablo Street, Suite 2000, Los Angeles, CA 90033, United States of America
| | - Amy H Tang
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, 1520 San Pablo Street, Suite 2000, Los Angeles, CA 90033, United States of America
| | - Sang-Hyun Park
- Orthopaedic Institute for Children, J. Vernon Luck Sr. Orthopaedic Research Center, University of California, Los Angeles, 403 West Adams Boulevard, Los Angeles, CA 90007, United States of America
| | - Jay R Lieberman
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, 1520 San Pablo Street, Suite 2000, Los Angeles, CA 90033, United States of America.
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91
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Tay LS, Palmer N, Panwala R, Chew WL, Mali P. Translating CRISPR-Cas Therapeutics: Approaches and Challenges. CRISPR J 2020; 3:253-275. [PMID: 32833535 PMCID: PMC7469700 DOI: 10.1089/crispr.2020.0025] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
CRISPR-Cas clinical trials have begun, offering a first glimpse at how DNA and RNA targeting could enable therapies for many genetic and epigenetic human diseases. The speedy progress of CRISPR-Cas from discovery and adoption to clinical use is built on decades of traditional gene therapy research and belies the multiple challenges that could derail the successful translation of these new modalities. Here, we review how CRISPR-Cas therapeutics are translated from technological systems to therapeutic modalities, paying particular attention to the therapeutic cascade from cargo to delivery vector, manufacturing, administration, pipelines, safety, and therapeutic target profiles. We also explore potential solutions to some of the obstacles facing successful CRISPR-Cas translation. We hope to illuminate how CRISPR-Cas is brought from the academic bench toward use in the clinic.
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Affiliation(s)
- Lavina Sierra Tay
- Laboratory of Synthetic Biology and Genome Editing Therapeutics, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Nathan Palmer
- Division of Biological Sciences, University of California San Diego, La Jolla, California, USA
| | - Rebecca Panwala
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Wei Leong Chew
- Laboratory of Synthetic Biology and Genome Editing Therapeutics, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Prashant Mali
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
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92
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Chandler LC, Yusuf IH, McClements ME, Barnard AR, MacLaren RE, Xue K. Immunomodulatory Effects of Hydroxychloroquine and Chloroquine in Viral Infections and Their Potential Application in Retinal Gene Therapy. Int J Mol Sci 2020; 21:E4972. [PMID: 32674481 PMCID: PMC7404262 DOI: 10.3390/ijms21144972] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 07/02/2020] [Accepted: 07/09/2020] [Indexed: 12/25/2022] Open
Abstract
Effective treatment of retinal diseases with adeno-associated virus (AAV)-mediated gene therapy is highly dependent on the proportion of successfully transduced cells. However, due to inflammatory reactions at high vector doses, adjunctive treatment may be necessary to enhance the therapeutic outcome. Hydroxychloroquine and chloroquine are anti-malarial drugs that have been successfully used in the treatment of autoimmune diseases. Evidence suggests that at high concentrations, hydroxychloroquine and chloroquine can impact viral infection and replication by increasing endosomal and lysosomal pH. This effect has led to investigations into the potential benefits of these drugs in the treatment of viral infections, including human immunodeficiency virus and severe acute respiratory syndrome coronavirus-2. However, at lower concentrations, hydroxychloroquine and chloroquine appear to exert immunomodulatory effects by inhibiting nucleic acid sensors, including toll-like receptor 9 and cyclic GMP-AMP synthase. This dose-dependent effect on their mechanism of action supports observations of increased viral infections associated with lower drug doses. In this review, we explore the immunomodulatory activity of hydroxychloroquine and chloroquine, their impact on viral infections, and their potential to improve the efficacy and safety of retinal gene therapy by reducing AAV-induced immune responses. The safety and practicalities of delivering hydroxychloroquine into the retina will also be discussed.
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Affiliation(s)
- Laurel C. Chandler
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; (I.H.Y.); (M.E.M.); (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Imran H. Yusuf
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; (I.H.Y.); (M.E.M.); (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Michelle E. McClements
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; (I.H.Y.); (M.E.M.); (A.R.B.); (R.E.M.)
| | - Alun R. Barnard
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; (I.H.Y.); (M.E.M.); (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; (I.H.Y.); (M.E.M.); (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; (I.H.Y.); (M.E.M.); (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
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93
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Ameri H, Murat C, Arbabi A, Jiang W, Janga SR, Qin PZ, Hamm-Alvarez SF. Reduced Expression of VEGF-A in Human Retinal Pigment Epithelial Cells and Human Muller Cells Following CRISPR-Cas9 Ribonucleoprotein-Mediated Gene Disruption. Transl Vis Sci Technol 2020; 9:23. [PMID: 32855870 PMCID: PMC7422915 DOI: 10.1167/tvst.9.8.23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 05/22/2020] [Indexed: 11/30/2022] Open
Abstract
Purpose To evaluate the effects of vascular endothelial growth factor-A (VEGF-A) gene editing in human retinal pigment epithelial (RPE) cells and human Muller cells, which are the main VEGF-A producing cells in the eye. Methods CRISPR-Cas9 ribonucleoprotein was used to target exon 1 in VEGF-A gene. Lipofectamine CRISPRMAX was used as a vehicle. In vitro gene editing efficiency was assessed on oligonucleotides and genomic DNAs. Sanger sequencing was performed to detect indels. VEGF-A messenger RNA and protein expressions were assessed using quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. Results In vitro cleavage assay on a 60-nucleotide DNA duplex showed 88% cleavage of the precursor. The cleavage efficiency was 40% in RPE cells and 32% in Muller cells. Sanger sequencing in the CRISPR-Cas9 treated RPE and Muller cells showed indels at the predicted cut site in both cells. After the VEGF-A gene disruption, VEGF-A protein levels decreased 43% in RPE cells (P < 0.0001) and 38% in Muller cells (P < 0.0001). Conclusions CRISPR-Cas9–mediated gene disruption resulted in a significant decrease in the VEGF-A gene protein expression in human RPE and Muller cells. CRISPR-Cas9 ribonucleoprotein may allow simultaneous targeting of multiple VEGF-A producing cells. Translational Relevance VEGF-A gene disruption using CRISPR-Cas9 ribonucleoprotein has a potential in treating retinal vascular diseases.
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Affiliation(s)
- Hossein Ameri
- USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Christopher Murat
- USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Amirmohsen Arbabi
- USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Wei Jiang
- USC Dornsife College of Letters, Arts and Sciences, Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Srikanth R Janga
- USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Peter Zhifeng Qin
- USC Dornsife College of Letters, Arts and Sciences, Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Sarah F Hamm-Alvarez
- USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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94
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Shen J, Kim J, Tzeng SY, Ding K, Hafiz Z, Long D, Wang J, Green JJ, Campochiaro PA. Suprachoroidal gene transfer with nonviral nanoparticles. SCIENCE ADVANCES 2020; 6:eaba1606. [PMID: 32937452 PMCID: PMC7458446 DOI: 10.1126/sciadv.aba1606] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/20/2020] [Indexed: 05/16/2023]
Abstract
Subretinal injections of viral vectors provide great benefits but have limited cargo capacity; they induce innate and adaptive immune responses, which may cause damage and preclude repeated injections; and they pose administration risks. As a new biotechnology, suprachoroidal injections of biodegradable nanoparticles (NPs) containing a reporter plasmid induce reporter expression in rat photoreceptors and RPE throughout the entire eye and maintain expression for at least 8 months. Multiple injections markedly increase expression. Suprachoroidal injection of NPs containing a VEGF expression plasmid caused severe subretinal neovascularization progressing to subretinal fibrosis, similar to what occurs in untreated patients with neovascular age-related macular degeneration, providing a new model and proof of concept for level and duration of expression. Suprachoroidal injection of NPs containing a VEGF-binding protein expression plasmid significantly suppressed VEGF-induced vascular leakage and neovascularization demonstrating therapeutic potential. These data suggest that nonviral NP suprachoroidal gene transfer may provide a noninvasive, repeatable alternative to subretinal injection of viral vectors.
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Affiliation(s)
- Jikui Shen
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jayoung Kim
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Stephany Y Tzeng
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kun Ding
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zibran Hafiz
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Da Long
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jiangxia Wang
- Johns Hopkins Biostatistics Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Jordan J Green
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter A Campochiaro
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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95
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Song H, Zeng Y, Sardar Pasha SPB, Bush RA, Vijayasarathy C, Qian H, Wei L, Wiley HE, Wu Z, Sieving PA. Trans-Ocular Electric Current In Vivo Enhances AAV-Mediated Retinal Transduction in Large Animal Eye After Intravitreal Vector Administration. Transl Vis Sci Technol 2020; 9:28. [PMID: 32844051 PMCID: PMC7416894 DOI: 10.1167/tvst.9.7.28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 05/06/2020] [Indexed: 01/25/2023] Open
Abstract
Purpose Electric micro-current has been shown to enhance penetration and transduction of adeno-associated viral (AAV) vectors in mouse retina after intravitreal administration. We termed this: “electric-current vector mobility (ECVM).” The present study considered whether ECVM could augment retinal transduction efficiency of intravitreal AAV8-CMV-EGFP in normal rabbit and nonhuman primate (NHP) macaque. Potential mechanisms underlying enhanced retinal transduction by ECVM were also studied. Methods We applied an electric micro-current across the intact eye of normal rabbit and monkey in vivo for a brief period immediately after intravitreal injection of AAV8-CMV-EGFP. Retinal GFP expression was evaluated by fundus imaging in vivo. Retinal immunohistochemistry was performed to assess the distribution of retinal cells transduced by the AAV8-EGFP. Basic fibroblast growth factor (bFGF) was analyzed by quantitative RT-polymerase chain reaction (PCR). Müller glial reactivity and inner limiting membrane (ILM) were examined by the glial fibrillary acidic protein (GFAP) and vimentin staining in mouse retina, respectively. Results ECVM significantly increased the efficiency of AAV reaching and transducing the rabbit retina following intravitreal injection, with gene expression in inner nuclear layer, ganglion cells, and Müller cells. Similar trend of improvement was observed in the ECVM-treated monkey eye. The electric micro-current upregulated bFGF expression in Müller cells and vimentin showed ILM structural changes in mouse retina. Conclusions ECVM promotes the transduction efficiency of AAV8-CMV-GFP in normal rabbit and monkey retinas following intravitreal injection. Translational Relevance This work has potential translational relevance to human ocular gene therapy by increasing retinal expression of therapeutic vectors given by intravitreal administration.
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Affiliation(s)
- Hongman Song
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yong Zeng
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Ronald A Bush
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Camasamudram Vijayasarathy
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Haohua Qian
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lisa Wei
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Henry E Wiley
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Zhijian Wu
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Paul A Sieving
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA.,Department of Ophthalmology, School of Medicine, University of California at Davis, Sacramento, CA, USA
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96
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Retinal gene therapy: an eye-opener of the 21st century. Gene Ther 2020; 28:209-216. [PMID: 32561864 DOI: 10.1038/s41434-020-0168-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 06/02/2020] [Accepted: 06/09/2020] [Indexed: 02/07/2023]
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97
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Kiss S, Grishanin R, Nguyen A, Rosario R, Greengard JS, Nieves J, Gelfman CM, Gasmi M. Analysis of Aflibercept Expression in NHPs following Intravitreal Administration of ADVM-022, a Potential Gene Therapy for nAMD. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 18:345-353. [PMID: 32671137 PMCID: PMC7341454 DOI: 10.1016/j.omtm.2020.06.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 06/08/2020] [Indexed: 12/21/2022]
Abstract
Several standard-of-care therapies for the treatment of retinal disease, including aflibercept, inhibit vascular endothelial growth factor (VEGFA). The main shortcoming of these therapies is potential undertreatment due to a lack of compliance resulting from the need for repeated injections. Gene therapy may provide sustained levels of anti-VEGFA proteins in the retina following a single injection. In this nonhuman primate study, we explored whether ADVM-022, a recombinant adeno-associated virus (AAV) vector designed to express aflibercept, could induce anti-VEGFA protein levels comparable with those observed following a single-bolus intravitreal (IVT) injection of the standard-of-care aflibercept recombinant protein. The results demonstrated that intraocular levels of aflibercept measured at 56 days after a single IVT injection of ADVM-022 were equivalent to those in the aflibercept recombinant protein-injected animals measured 21–32 days post-administration. ADVM-022-injected animals exhibited signs of an initial self-limiting inflammatory response, but overall all doses were well tolerated. ADVM-022 administration did not result in systemic exposure to aflibercept at any dose evaluated. These results demonstrated that a single IVT injection of ADVM-022 resulted in safe and efficacious aflibercept levels in the therapeutic range, suggesting the potential of a gene therapy approach for long-term treatment of retinal disease with anti-VEGF therapy.
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Affiliation(s)
- Szilárd Kiss
- Weill Cornell Medical College, New York, NY, USA
| | | | | | | | | | | | | | - Mehdi Gasmi
- Adverum Biotechnologies, Menlo Park, CA, USA
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98
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Buck TM, Wijnholds J. Recombinant Adeno-Associated Viral Vectors (rAAV)-Vector Elements in Ocular Gene Therapy Clinical Trials and Transgene Expression and Bioactivity Assays. Int J Mol Sci 2020; 21:E4197. [PMID: 32545533 PMCID: PMC7352801 DOI: 10.3390/ijms21124197] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 02/06/2023] Open
Abstract
Inherited retinal dystrophies and optic neuropathies cause chronic disabling loss of visual function. The development of recombinant adeno-associated viral vectors (rAAV) gene therapies in all disease fields have been promising, but the translation to the clinic has been slow. The safety and efficacy profiles of rAAV are linked to the dose of applied vectors. DNA changes in the rAAV gene cassette affect potency, the expression pattern (cell-specificity), and the production yield. Here, we present a library of rAAV vectors and elements that provide a workflow to design novel vectors. We first performed a meta-analysis on recombinant rAAV elements in clinical trials (2007-2020) for ocular gene therapies. We analyzed 33 unique rAAV gene cassettes used in 57 ocular clinical trials. The rAAV gene therapy vectors used six unique capsid variants, 16 different promoters, and six unique polyadenylation sequences. Further, we compiled a list of promoters, enhancers, and other sequences used in current rAAV gene cassettes in preclinical studies. Then, we give an update on pro-viral plasmid backbones used to produce the gene therapy vectors, inverted terminal repeats, production yield, and rAAV safety considerations. Finally, we assess rAAV transgene and bioactivity assays applied to cells or organoids in vitro, explants ex vivo, and clinical studies.
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Affiliation(s)
- Thilo M. Buck
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands;
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands;
- Netherlands Institute of Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, The Netherlands
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99
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Chung SH, Mollhoff IN, Nguyen U, Nguyen A, Stucka N, Tieu E, Manna S, Meleppat RK, Zhang P, Nguyen EL, Fong J, Zawadzki R, Yiu G. Factors Impacting Efficacy of AAV-Mediated CRISPR-Based Genome Editing for Treatment of Choroidal Neovascularization. Mol Ther Methods Clin Dev 2020; 17:409-417. [PMID: 32128346 PMCID: PMC7044682 DOI: 10.1016/j.omtm.2020.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 01/14/2020] [Indexed: 12/12/2022]
Abstract
Frequent injections of anti-vascular endothelial growth factor (anti-VEGF) agents are a clinical burden for patients with neovascular age-related macular degeneration (AMD). Genomic disruption of VEGF-A using adeno-associated viral (AAV) delivery of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 has the potential to permanently suppress aberrant angiogenesis, but the factors that determine the optimal efficacy are unknown. Here, we investigate two widely used Cas9 endonucleases, SpCas9 and SaCas9, and evaluate the relative contribution of AAV-delivery efficiency and genome-editing rates in vivo to determine the mechanisms that drive successful CRISPR-based suppression of VEGF-A, using a mouse model of laser-induced choroidal neovascularization (CNV). We found that SpCas9 demonstrated higher genome-editing rates, greater VEGF reduction, and more effective CNV suppression than SaCas9, despite similar AAV transduction efficiency between a dual-vector approach for SpCas9 and single-vector system for SaCas9 to deliver the Cas9 orthologs and single guide RNAs (gRNAs). Our results suggest that successful VEGF knockdown using AAV-mediated CRISPR systems may be determined more by the efficiency of genome editing rather than viral transduction and that SpCas9 may be more effective than SaCas9 as a potential therapeutic strategy for CRISPR-based treatment of CNV in neovascular AMD.
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Affiliation(s)
- Sook Hyun Chung
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Iris Natalie Mollhoff
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Uyen Nguyen
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Amy Nguyen
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Natalie Stucka
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Eric Tieu
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Suman Manna
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Ratheesh Kumar Meleppat
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Pengfei Zhang
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Emerald Lovece Nguyen
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Jared Fong
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Robert Zawadzki
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
| | - Glenn Yiu
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, CA, USA
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100
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Boye SL, Choudhury S, Crosson S, Di Pasquale G, Afione S, Mellen R, Makal V, Calabro KR, Fajardo D, Peterson J, Zhang H, Leahy MT, Jennings CK, Chiorini JA, Boyd RF, Boye SE. Novel AAV44.9-Based Vectors Display Exceptional Characteristics for Retinal Gene Therapy. Mol Ther 2020; 28:1464-1478. [PMID: 32304666 PMCID: PMC7264435 DOI: 10.1016/j.ymthe.2020.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/28/2020] [Accepted: 04/02/2020] [Indexed: 01/13/2023] Open
Abstract
The majority of inherited retinal diseases (IRDs) are caused by mutations in genes expressed in photoreceptors (PRs). The ideal vector to address these conditions is one that transduces PRs in large areas of retina with the smallest volume/lowest titer possible, and efficiently transduces foveal cones, the cells responsible for acute, daylight vision that are often the only remaining area of functional retina in IRDs. The purpose of our study was to evaluate the retinal tropism and potency of a novel capsid, AAV44.9, and rationally designed derivatives thereof. We found that AAV44.9 and AAV44.9(E531D) transduced retinas of subretinally injected (SRI) mice with higher efficiency than did benchmark AAV5- and AAV8-based vectors. In macaques, highly efficient cone and rod transduction was observed following submacular and peripheral SRI. AAV44.9- and AAV44.9(E531D)-mediated GFP fluorescence extended laterally well beyond SRI bleb margins. Notably, extrafoveal injection (i.e., fovea not detached during surgery) led to transduction of up to 98% of foveal cones. AAV44.9(E531D) efficiently transduced parafoveal and perifoveal cones, whereas AAV44.9 did not. AAV44.9(E531D) was also capable of restoring retinal function to a mouse model of IRD. These novel capsids will be useful for addressing IRDs that would benefit from an expansive treatment area.
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Affiliation(s)
- Sanford L. Boye
- Department of Pediatrics and the Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
| | - Shreyasi Choudhury
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Sean Crosson
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Giovanni Di Pasquale
- Adeno-Associated Virus Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Sandra Afione
- Adeno-Associated Virus Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Russell Mellen
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Victoria Makal
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Kaitlyn R. Calabro
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Diego Fajardo
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - James Peterson
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Hangning Zhang
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Matthew T. Leahy
- Ophthalmology Services, Charles River Laboratories, Mattawan, MI, USA
| | - Colin K. Jennings
- Ophthalmology Services, Charles River Laboratories, Mattawan, MI, USA
| | - John A. Chiorini
- Adeno-Associated Virus Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Ryan F. Boyd
- Ophthalmology Services, Charles River Laboratories, Mattawan, MI, USA
| | - Shannon E. Boye
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA,Corresponding author: Shannon E. Boye, Department of Ophthalmology, University of Florida, P.O. Box 100284, Gainesville, FL 32610, USA.
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